A toolkit applet executed in a Universal Subscriber Identity Module (USIM) card is equipped with a communication processing function to perform Over The Air (OTA) communication or Bearer Independent Protocol (BIP)/Transmission Control Protocol (TCP)/User Datagram Protocol (UDP) communication with a mobile network operator server.
FIG. 1 is a view illustrating a program architecture of the USIM card. As shown in FIG. 1, the USIM card includes a plurality of toolkit applets 11, 12, and 13 installed therein to perform different services, in addition to a toolkit framework 20 and a Card Operating System (COS) 30.
The toolkit applets 11, 12, and 13 are equipped with their respective communication processing functions to perform necessary communication processes directly.
FIG. 2 is a table showing communication schemes of the toolkit applets 11, 12, and 13. Referring to FIGS. 1 and 2, 1) the toolkit applet-1 11 executes communication processes only according to OTA, 2) the toolkit applet-2 12 executes communication processes only according to OTA and TCP, and 3) the toolkit applet-3 13 executes communication processes only according to TCP and UDP.
In order for the toolkit applet-1 11 to execute communication processes according to TCP, TCP communication processing function should be added to the toolkit applet-1 11, which may cause inconvenience in programming.
In addition, addition of the communication processing function to the toolkit applets 11, 12, and 13 makes it difficult to develop toolkit applets. In addition, since the toolkit applets 11, 12, and 13 are equipped with overlapping communication processing functions, the capacity of the applet increases and thus a high capacity memory is required.
With the recent development of the mobile network and the advent of various mobile services, the communication between the server and the USIM card is becoming more frequent and the amount of data exchanged therebetween is increasing. Therefore, the number of toolkit applets requiring BIP communication in addition to OTA communication is increasing.
In this situation, since the capacity of the toolkit applet increases and the demand for a high-capacity memory increase, it is difficult to develop the toolkit applets and the manufacturing cost of the USIM card increases.